1. Field of the Invention
This invention relates to an electrophotographic apparatus in which cut sheet and continuous paper such as fanfold paper and rolled paper can be selectively used, and a method for electrophotographic process on the cut sheet and continuous paper.
2. Description of the Related Art
An electrophotographic apparatus designed to selectively print data on cut sheet or continuous paper is disclosed in U.S. Pat. Nos. 4,929,282 and 4,941,377, for example. The electrophotographic apparatus disclosed in the above U.S.P. documents includes a common paper feeding path for feeding one of the printing papers of cut sheet and continuous paper and effects the electrophotographic process for the printing paper in the process of feeding the printing paper along the common paper feeding path. That is, while the printing paper is fed along the common paper feeding path, a toner image is transferred to the printing paper when it comes to an image transferring position which is previously determined on the common feeding path and then the toner image is fixed on the printing paper in the fixing position which is defined on the downstream side of the transferring position.
In the known electrophotographic apparatus, paths for supplying cut sheet and continuous paper to the common feeding path are different and methods for supplying paper in the respective supplying paths are different from each other. As a result, when a print starting command signal is generated and cut sheet or continuous paper is fed to the transferring position on the common feeding path via the corresponding paper supplying path, transferring timings at which the cut sheet and continuous paper are fed to the transferring position after generation of the print starting command signal are different from each other. Therefore, if the transferring timing is determined according to the feeding operation of one of the two types of printing papers, then it becomes impossible to correctly transfer a toner image onto the other type printing paper. In this case, if flash light is used for fixing the toner image, not only the transferring timing but also the fixing timing is deviated and part of the toner image may be kept unfixed.
When a flash type fixing unit is used, the quality of fixing may be deteriorated unless uniform light energy is applied to the toner image on the printing paper or to the printing surface.
Further, when continuous paper is used, it is preferable to automatically cut off the continuous paper after a sequence of printing operations is effected. However, when fanfold paper is used as the continuous paper, the perforation line of the fanfold paper to be cut off must be aligned with the cutting position, making it difficult to correctly cut off the fanfold paper.